Evaluation of mis-matching units

[jsakas]

Hi, in reviewing the tests it looks like mis-matching units are evaluated, for example:

test(
  'should reduce nested expression',
  testFixture,
  'calc( (1em - calc( 10px + 1em)) / 2)',
  '-5px'
)

I'm unsure how this equates to 5px unless you are also converting em to px.

Based on current browser implementations, mis-matching units are not evaluated and this would get converted to calc((1em - (10px + 1em)) / 2). I am wondering if this evaluation is intentional or a a bug.

[andyjansson]

The calculation looks right to me.

(1em - (10px + 1em) / 2) is the same thing as ((1em - 1em) - 10px) / 2).
1em - 1em equals 0. You're left with -10px / 2 which equals -5px.